PATHOGENIC OR POTENTIALLY PATHOGENIC BACTERIA AS CONTAMINANTS OF FRESH-WATER FROM DIFFERENT SOURCES IN ARARAQUARA, BRAZIL

The microbiological quality of various fresh waters in the Araraquara region, state of São Paulo, Brazil was investigated. Ninety-nine water samples were taken from rivers, reservoirs, artesian and non-artesian wells, springs and tap waters, and these waters were analysed using: plate counts of heterotrophic microorganisms (per 1 ml); Most Probable Number (MPN) of fecal coliforms and E. coli (per 100 ml); tests for presence of Salmonella, Shigella, Yersinia, the E. coli pathogens of classes EPEC, ETEC and EIEC and Mycobacterium, Shigella, Yersinia and enteroinvasive E. coli (EIEC) were not isolated. The other types of microorganisms were isolated in varying proportions. We conclude that the waters investigated represent a potential microbiological health risk.

STUDY OF AMNONIFYING BACTERIA BEHAVIOR IN THE LAKES CARIOCA AND D-HELVECIO (RIO-DOCE-VALLEY-MG)

The study of the amnonifying bacteria behavior in the lakes Carioca and D. Helvecio, which belong to the natural lacustrine system of the Rio Doce Valley - Minas Gerais - Brazil, during the period from March to November, showed a similar seasonal variation in both lakes, with higher population density in March and November (raining period) and lower density in May, July and September (dry period). The vertical variation was also relatively similar for both lakes, were during the thermal stratification the distribution was regular along the water column, while during the period of thermal stratification the populational density was remarkably different at different depths. The characterized ammonifying types to the genera Acinetobacter, Moraxella and Proteus, which in culture reveal high amnonifying activity with values which have reached 30,8 mug/l of ammonia per population unity (105 bacteria/ml).

The influence of fermentation time and the presence of salts in the rheology of the fermentation broth of a polysaccharide-producing bacteria free of soil

Rheological studies were carried out in the fermentation broth of a polysaccharide-producing microorganism free of soil. This microorganism was designated 4B. The bacteria 4B was inoculated in the fermentation broth, which consisted of a carbon source and mineral salts, and it was incubated in a rotating agitator at 30 degreesC for 72 h at 210 rpm. A rheometer of concentric cylinders equipped with a thermostatic bath was used and the readings were taken at 25 degreesC. A study was made of the influence of the fermentation time and the readings were made after 24, 48 and 72 h of incubation, using, separately, sucrose and glucose as carbon sources. The influence of the salt concentrations was determined in each carbon source; the salts used were NaCl, KCl and CaCl2 in the concentrations of 0.4%, 1.0%, 2.0% and 3.0%. It was observed that the fermentation broth behaves as a non-Newtonian fluid and it presents pseudoplastic behaviour. Calculations were made of the flow behaviour index (n) and the consistency index (k) of the samples after 24, 48 and 72 h of fermentation, and it was observed that the 72 h sample presented higher k and consequently higher apparent viscosity. of the carbon sources used, the sucrose presented higher viscous broths after 24 and 48 h, and the glucose after 72 h of fermentation. With relation to the effect of the addition of salts, the CaCl2 presented a higher influence on the viscosity of the fermentation broths. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Chlorine dioxide against bacteria and yeasts from the alcoholic fermentation

The ethanol production in Brazil is carried out by fed-batch or continuous process with cell recycle, in such way that bacterial contaminants are also recycled and may be troublesome due to the substrate competition. Addition of sulphuric acid when inoculum cells are washed can control the bacterial growth or alternatively biocides are used. This work aimed to verify the effect of chlorine dioxide, a well-known biocide for bacterial decontamination of water and equipments, against contaminant bacteria ( Bacillus subtilis, Lactobacillus plantarum, Lactobacillus fermentum and Leuconostoc mesenteroides) from alcoholic fermentation, through the method of minimum inhibitory concentration ( MIC), as well as its effect on the industrial yeast inoculum. Lower MIC was found for B. subtilis ( 10 ppm) and Leuconostoc mesenteroides ( 50 ppm) than for Lactobacillus fermentum ( 75 ppm) and Lactobacillus plantarum ( 125 ppm). Additionally, these concentrations of chlorine dioxide had similar effects on bacteria as 3 ppm of Kamoran (R) ( recommended dosage for fermentation tanks), exception for B. subtilis, which could not be controlled at this Kamoran (R) dosage. The growth of industrial yeasts was affected when the concentration of chlorine dioxide was higher than 50 ppm, but the effect was slightly dependent on the type of yeast strain. Smooth yeast colonies ( dispersed cells) seemed to be more sensitive than wrinkled yeast colonies ( clustered cells/pseudohyphal growth), both isolated from an alcohol-producing unit during the 2006/2007 sugar cane harvest. The main advantage in the usage of chlorine dioxide that it can replace antibiotics, avoiding the selection of resistant populations of microorganisms.

Interaction Between the Predator Podisus nigrispinus (Hemiptera: Pentatomidae) and the Entomopathogenic Bacteria Bacillus thuringiensis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Uptake of bacteria by trophozoites of Giardia duodenalis (Say)

Rod-like bacteria were found in the cytoplasm of trophozoites of Giardia duodenalis (Say) in domestic rats (Rattus rattus). These structures were always in phagocytic vacuoles without signs of bacteria digestion or degradation of the trophozoite cytoplasm. The uptake of the bacteria was observed from their attachment to the trophozoite membrane until their total incorporation by phagocytosis.

Adherence and experimental infection of bacteria associated with periodontal infections of young cattle in Brazil (Cara inchada)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inhibitory activity of glass-ionomer cements on cariogenic bacteria

This study evaluated the antibacterial activity of the glass-ionomer cements Vitrebond (3M ESPE), Ketac Molar (3M ESPE) and Fuji IX (GC America) against S mutans, S sobrinus, L acidophilus and A viscosus, using the agar diffusion test. Inocula were obtained by the seed of indicators cultures in BHI broth incubated at 37°C for 24 hours. Base layers containing 15 mL of BHI agar and 300 μL of each bacteria suspension were prepared in Petri dishes. Six wells measuring 4 mm in diameter were made in each plate and completely filled with one of the testing materials. A 0.2% chlorhexidine solution applied in round filter papers was used as control. Tests were performed 12 times for each material and bacteria strain. After incubation of the plates at 37°C for 24 hours, the zones of bacterial growth inhibition around the wells were measured. Overall, the results showed the following sequence of antibacterial activity: Vitrebond (despite the activation mode) > 0.2% chlorhexidine > Ketac Molar > Fuji IX, according to Kruskal-Wallis and Mann-Whitney statistical tests. This study confirmed significant antibacterial activity for two conventional glass-ionomers and one resin-modified glass-ionomer material. The resin-modified glass-ionomer cement Vitrebond, regardless of the activation mode, presented the best antibacterial activity against S mutans and S sobrinus. The antibacterial activity against A viscosus for Vitrebond was similar to 0.2% chlorhexidine, while light activation reduced its antibacterial activity against L acidophilus. ©Operative Dentistry, 2005.

Benzopyrans from Curvularia sp., an endophytic fungus associated with Ocotea corymbosa (Lauraceae)

An isolate of Curvularia sp. was obtained from the leaves of Ocotea corymbosa, a native plant of the Brazilian Cerrado. The ethyl acetate extract from culture of this fungus afforded two benzopyran derivatives: (2′S)-2-(propan-2′-ol)-5-hydroxy-benzopyran-4-one (2) and 2,3-dihydro-2-methyl-benzopyran-4,5-diol (4); and two known benzopyrans: 2-methyl-5-methoxy-benzopyran-4-one (1) and (2R)-2,3-dihydro-2-methyl-5-methoxy- benzopyran-4-one (3). The structures of 2 and 4 were established on the basis of comprehensive spectroscopic analysis, mainly using 1D and 2D NMR experiments. The benzopyrans 1 and 2 showed weak in vitro antifungal activity against Cladosporium sphaerospermum and C. cladosporioides. Analyses of the biological activities were also carried out on HeLa (human cervix tumor) and CHO (Chinese hamster ovary) cells, aiming to evaluate their potential effects on mammalian cell line proliferation. Results from both cell lines indicated that compound 2 was able to induce cell proliferation: 70% on HeLa cells and 25% on CHO cells. © 2005 Elsevier Ltd. All rights reserved.

Endophytic yeasts and filamentous fungi associated with southern Brazilian apple (Malus domestica) orchards subjected to conventional, integrated or organic cultivation

Endophytic fungi were isolated from leaves, flowers and fruit of healthy apple trees (Malus domestica, BORKH.) growing in southern Brazilian orchards under three different cultivation systems (conventional, integrated and organic), during two vegetative cycles. The greatest total number of endophytic isolates was obtained from the orchards under organic cultivation when compared to integrated and conventional cultivation systems. Filamentous fungi from the genera Colletotrichum, Xylaria and Botryosphaeria were the most frequent ones and the most representative yeast genera were Sporobolomyces, Rhodotorula, Debaryomyces and Cryptococcus. It is suggested that some isolates may be used as indicators of the different management systems. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.

New bioactive metabolites produced by Phomopsis cassiae, an endophytic fungus in Cassia spectabilis

Two new metabolites, ethyl 2,4-dihydroxy-5,6-dimethylbenzoate (1) and phomopsilactone (2) were isolated from Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures were elucidated by 1D and 2D NMR, MS and IR spectral data. Compounds 1 and 2 displayed strong antifungal activity against the phytopatogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as cytotoxicity against human cervical tumor cell line (HeLa), in in vitro assays. ©2005 Sociedade Brasileira de Química.

Faecal contamination (viral and bacteria) detection in groundwater used for drinking purposes in São Paulo, Brazil

This project has been developed to evaluate the possible relationship between the cesspit (pit latrine) in as far as it degrades the quality of underground water. Its importance is due to the fact that in the rural communities in the State of São Paulo (Brazil) this type of cesspit is very common as a means of sewage disposal and these communities use underground water for their supply of drinking water. Rural properties distributed over the rural area in the municipality of São José do Rio Preto were selected. A preliminary study was then set up to determine the social situation and health of the households as well as qualitative evaluations on the type of water supply and sewage disposal of these communities. Campaigns of water sampling then followed and laboratory analyses of water taken from wells were carried out. Parameters were set up to evaluate the potability according to Brazilian legislation (2004) paying attention to microbiologic (coliforms, Crytosporidium sp., and adenovirus). The analyses showed evidence of possible interaction between the wells and the sewage effluents and drainage in these communities. A PCR reaction to detect adenovirus showed a presence in 53.3% of the samples. The tests for the detection of Cryotosporidium sp all showed a negative result.